<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="leaveIndex" @mouseenter="enterShow">
        <h2 class="all">全部商品分类</h2>
        <transition name="sort">
          <div class="sort" v-show="isTypeShow">
            <div class="all-sort-list2" @click.prevent="goSearch($event)">
              <!-- 一级分类 -->
              <div class="item" v-for="(clFirst, index) in categoryList" :key="clFirst.categoryId"
                :class="{ curr: currentIndex == index }">
                <h3 @mouseenter="changeIndex(index)">
                  <a href="" :data-categoryname="clFirst.categoryName" :data-category1id="clFirst.categoryId">{{
                    clFirst.categoryName }}</a>
                  <!-- <router-link to="/search">{{ clFirst.categoryName }}</router-link> -->
                </h3>
                <!-- 二级分类、三级分类 -->
                <div class="item-list clearfix" v-show="currentIndex === index">
                  <div class="subitem">
                    <dl class="fore" v-for="clSecond in clFirst.categoryChild" :key="clSecond.categoryId">
                      <dt>
                        <a href="" :data-categoryname="clSecond.categoryName" :data-category2id="clSecond.categoryId">{{
                          clSecond.categoryName }}</a>
                        <!-- <router-link to="/search">{{ clSecond.categoryName }}</router-link> -->
                      </dt>
                      <dd>
                        <em v-for="clThird in clSecond.categoryChild" :key="clThird.categoryId">
                          <a href="" :data-categoryname="clThird.categoryName" :data-category3id="clThird.categoryId">{{
                            clThird.categoryName }}</a>
                          <!-- <router-link to="/search">{{ clThird.categoryName }}</router-link> -->
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>

    </div>
  </div>
</template>

<script>
import { mapState } from 'vuex';
import throttle from 'lodash/throttle';

export default {
  name: 'TypeNav',
  data() {
    return {
      // 存储用户鼠标悬浮在哪一个导航上
      currentIndex: -1,
      isTypeShow: false,
    }
  },
  computed: {
    ...mapState('home', ['categoryList']),
  },
  mounted() {
    if (this.$route.name === 'home') {
      this.isTypeShow = true;
    }
  },
  methods: {
    // 修改当前应该显示背景的下标
    changeIndex: throttle(function (hoverIndex) {
      this.currentIndex = hoverIndex;
    }, 10),
    // 鼠标离开导航消失背景颜色
    leaveIndex() {
      this.currentIndex = -1;
      // 鼠标离开消失
      if (this.$route.name !== 'home') {
        this.isTypeShow = false;
      }
    },
    // 前往搜索路由
    goSearch($event) {
      let { categoryname, category1id, category2id, category3id } = $event.target.dataset;
      if (!categoryname) {
        return;
      }
      let location = { name: 'search', query: { categoryName: categoryname } };
      if (category1id) {
        location.query.category1Id = category1id;
      } else if (category2id) {
        location.query.category2Id = category2id;
      } else if (category3id) {
        location.query.category3Id = category3id;
      }
      if (JSON.stringify(this.$route.params) != '{}') {
        location.params = this.$route.params;
      }
      this.$router.push(location);
      this.isTypeShow = false;
    },
    // 鼠标进入显示
    enterShow() {
      this.isTypeShow = true;
    }
  }
}
</script>

<style lang="less" scoped>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            // css方式
            // display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }
        }

        .curr {
          background-color: skyblue;
        }
      }
    }

    // 进入的起点
    // 离开的终点
    .sort-enter,
    .sort-leave-to {
      height: 0;
      opacity: 0;
    }

    .sort-enter-active,
    .sort-leave-active {
      transition: all .2s;
    }

    .sort-enter-to,
    .sort-leave {
      height: 461px;
      opacity: 1;
    }
  }
}
</style>